owncloud/core

Bugfix: Add very minimal empty ODF files

These files contain no data at all. This guarantees that when the
user opens a new document in the richdocuments app, the language
of paragraph, page size, cell date format, currency, etc. will be
according to the current locale.

Previous files were in German. E.g. document language (spellcheck
language) was set to German, spreadsheet tab name was "Tabelle",
etc. It was incorrect for non-German users.

https://github.com/owncloud/core/pull/37896